1. Field of the Invention
The present invention relates to an image forming apparatus with a character-writing function, and to a method of performing this function. More particularly, the present invention relates to an image forming apparatus capable of copying an original image and of writing characters, and to a method of performing the character writing.
2. Description of the Related Art
Recently, an electronic copying machine has been developed in which the pictorial information including characters that are different from a copied original image is written on a paper as a recording medium. The recording paper having an original image copied therein is led to an image forming section. Another image such as characters is formed on the recording paper bearing the original image in the image forming section. Thus, the above electronic copying machine requires two steps for the image formation, a step of forming an original image and a step of forming another image. Accordingly, the image forming speed of the copying machine is slow, compared to the corresponding image forming speed of the one-step image formation. Further, it is difficult to exactly position the image written after the original image is copied.
There has been developed another type of copying machine of the type in which an image is read from an original and the image data is then converted into electrical signals, and the original image is reproduced by using the converted electrical signals. This type of copying machine is called a digital copying machine. In the case of the digital copying machine, for example, a laser printer, the additional image including characters can be written on the recording paper while an original image is being copied. However, the digital copying machine is more expensive than the ordinary electronic copying machine.